Millions of older Americans experience cognitive declines as they age. Millions of older adults have sensory deficits that affect more than one sense. The focus to date on sensory decline, however, has been almost exclusively placed on simple clinical measures of threshold sensitivity in each sense. Based on our recently completed work, there is reason to believe that measures of temporal processing may be more sensitive to the effects of aging than measures of threshold sensitivity. In addition, our emerging model demonstrates that temporal processing in multiple senses is strongly associated with cognitive function (regardless of age). Our laboratory has developed an unprecedented cross-sectional data set on various aspects of temporal processing, from temporal acuity to temporal-order identification in three senses: hearing, vision, and touch. For the main baseline data set, data are available from 195 middle-aged and older adults tested on 34 sensory-processing measures using reliable, rigorous psychophysical methods. These data have permitted analysis and modeling of individual differences in performance within and across age groups; analyses that have heretofore not been possible. Age-group differences between young and older adults were also examined and were nearly universal among the set of 34 temporal-processing dependent measures included in our study. Although supportive of likely age-related changes in temporal processing, these changes require confirmation with longitudinal data on temporal processing. The gathering of such data from 195 middle-aged and older adults at 7 and 10 years following completion of the initial set of baseline measures represents the specific aim of the proposed project. In addition, there may be cognitive-health consequences for those middle-aged and older adults who exhibit poor temporal acuity and temporal-order identification in multiple senses. Individuals who exhibited this pattern of performance in the baseline cohort of 195 middle-aged and older adults, for example, had worse cognitive function. The greater the number of sensory processes impaired, the greater the cognitive decline. The longitudinal data to be gathered here will provide fundamental new knowledge about age-related sensory decline and also determine whether declines in sensory processing precede cognitive declines in older adults as hypothesized. If this hypothesis is confirmed, these findings could prove critical to the early diagnosis of cognitive decline in older adults and, ultimately, may lead to new approaches to intervention as well.